"On this very difficult day, we offer heartfelt condolences to today's victims and their families," the website reads. "Our City is working tirelessly to get as much information out to the families so they can begin the grieving process. Please keep the following individuals in your thoughts and prayers."

One of the victims, Edward Sotomayor, was the brand manager for a travel company and a former sales manager for a gay and lesbian lifestyle publication. A friend shared a video to Facebook that he said Sotomayor had sent from inside the club before the shooting. "My people are here," Sotomayor had said in the video, according to the post.

Sotomayor was known as "Top Hat Eddie" to his friends for his love of top hats.

Almodovar, who friends called kind and humble, was an administrative pharmacy technician from Massachusetts who was living in Clermont, Florida, according to his Facebook profile.

"We'll miss you Stanley," one friend wrote on his page. "You made an impact on everyone that you came around. A good person and friend."

Juan Ramon Guerrero was a student at the University of Central Florida. The 22-year-old was described as "a beautiful soul."

Twenty-year-old victim Omar Ocasio-Capo is one of the youngest who died. He was a barista at Starbuck's.

Mercedez Flores worked at Target and was at Pulse for a "girl's night out" when she was murdered.

Kimberly Morris had moved to Florida from Connecticut just months earlier. She was a bouncer at Pulse.

On Facebook, Gonzalez-Cruz's mother thanked friends for their kind words. "I thank you from the bottom of my heart for all the love that you have shown me regarding my son," she wrote.

"As a mother, I feel a deep and immense pain as everyone else who's going through this," she added.

Families of missing club-goers have been gathering at the Hampton Inn & Suites in Orlando, anxiously waiting for any updates about their loved ones.

On Sunday morning, ABC News reported that one mother, Christine Leinonen, is waiting for word on her son’s whereabouts — after his friend posted on Facebook that they had been at the club.

"They said there's a lot of dead bodies at the club and that's a crime scene and they can't identify anybody so it could be hours and hours before we find out,” she said.

She last spoke to her son, Christopher, around 6 p.m. Saturday. "I left him with 'I love you, Chris,'" she said.

On Monday morning, she told the Today show that she had still hadn't received confirmation that he was among the victims, but no hospitals had contacted her to say he was alive.

Tributes were popping up across the U.S. for the victims. Organizers of the Tony Awards said the show on Sunday night would be dedicated to those who were killed in the attack, while attendees were given small white ribbons in remembrance of the victims.

In New York City, the Empire Building’s lights were dark “in sympathy for the victims of last night’s attack in Orlando,” according to its Twitter page.

One World Trade Center was lit in the colors of the pride flag to honor the LGBT community and those who lost their lives in the attack.

The gunman opened fire in the nightclub in the early hours of Sunday morning. He had pledged allegiance to ISIS, and the terror group has since claimed responsibility for the attack.